Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-23T15:02:54.704Z Has data issue: false hasContentIssue false
  • English
  • Français

Interrelationships between physical and metabolic control of voluntary food intake in fattening, pregnant and lactating mature sheep: a model

Published online by Cambridge University Press:  02 September 2010

J. M. Forbes
J. M. Forbes
Affiliation:
Department of Animal Physiology and Nutrition, University of Leeds, Leeds LS2 9JT
Get access

Summary

A model has been developed in which the voluntary food intake of sheep is related directly to metabolizable energy requirements unless physical or endocrine limitations intervene.

Although no ‘set point’ for body weight or body fat is incorporated in the model, mature sheep offered food ad libitum are predicted to reach eventually a plateau of body weight due to progressive depression of gut capacity by the increasing volume of abdominal fat. The final body weight is proportional to the digestibility of the diet. During pregnancy and lactation metabolic, physical and endocrine factors interact in such a way as to give predicted patterns of feed intake similar to those observed in practice with several qualities of diet.

Type
Research Article
Information
Animal Production , Volume 24 , Issue 1 , February 1977 , pp. 91 - 101
Copyright
Copyright © British Society of Animal Science 1977

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Agricultural Research Council. 1965. The Nutrient Requirements of Farm Livestock. No. 2, Ruminants. Agricultural Research Council, London.Google Scholar
Ammann, A. P., Cowan, R. L., Mothershead, C. L. and Baumgardt, B. R. 1973. Dry matter and energy intake in relation to digestibility in white-tailed deer. J. Wildl Mgmt 37: 195–201.CrossRefGoogle Scholar
Armstrong, J. S. 1971. Modelling a grazing system. Proc. Ecol. Soc. Aust. 6: 194–202.Google Scholar
Baile, C. A. and Forbes, J. M. 1974. Control of feed intake and regulation of energy balance in ruminants. Physiol. Rev. 54: 160–214.CrossRefGoogle ScholarPubMed
Baile, C. A., Mayer, J., Mahoney, A. W. and McLaughlin, C. 1969. Hypothalamic hyperphagia in goats and some observations of its effect on glucose utilization rate. J. Dairy Sci. 52: 101–109.CrossRefGoogle ScholarPubMed
Baumgardt, B. R. 1970. Control of feed intake and energy balance. In Physiology of Digestion and Metabolism in the Ruminant (ed. Phillipson, A. T.), pp. 235–253. Oriel Press, Newcastle-upon-Tyne.Google Scholar
Campling, R. C. 1970. Physical regulation of voluntary intake. In Physiology of Digestion and Metabolism in the Ruminant (ed. Phillipson, A. T.), pp. 226–234. Oriel Press, Newcastle-upon-Tyne.Google Scholar
Challis, J. R. G., Harrison, F. A. and Heap, R. B. 1973. The kinetics of oestradiol-17β metabolism in the sheep. J. Endocr. 57: 97–110.CrossRefGoogle ScholarPubMed
Conrad, H. R., Pratt, A. D. and Hibbs, J. W. 1964. Regulation of feed intake in dairy cows. 1. Change in importance of physical and physiological factors with increasing digestibility. J. Dairy Sci. 47: 54–62.CrossRefGoogle Scholar
Davies, H. L. 1962. Intake studies in sheep involving high fluid intake. Proc. Aust. Soc. Anim. Prod. 4: 167–171.Google Scholar
Edelsten, P. R. and Newton, J. E. 1975. A simulation model of intensive lamb production from grass. Tech. Rep. Grassld Res. Inst., No. 17.Google Scholar
Foot, J. Z. 1972. A note on the effect of body condition on the voluntary intake of dried grass wafers by Scottish Blackface ewes. Anim. Prod. 14: 131–134.Google Scholar
Forbes, J. M. 1968. The effect of pregnancy on rumen volume and voluntary feed intake in the ewe. Ph.D. Thesis, Univ. Leeds.Google Scholar
Forbes, J. M. 1969. The effect of pregnancy and fatness on the volume of rumen contents in the ewe. J. agric. Sci., Camb. 72: 119–121.CrossRefGoogle Scholar
Forbes, J. M. 1970a. The voluntary food intake of pregnant and lactating ruminants. A review. Br. vet. J. 126: 1–11.CrossRefGoogle ScholarPubMed
Forbes, J. M. 1970b. Voluntary food intake of pregnant ewes. Anim. Sci. 31: 1222–1227.CrossRefGoogle Scholar
Forbes, J. M. 1971. Physiological changes affecting voluntary food intake in ruminants. Proc. Nutr. Soc. 30: 135–142.CrossRefGoogle ScholarPubMed
Forbes, J. M. 1974. Feeding in sheep modified by intraventricular estradiol and progesterone. Physiol. Behav. 12: 741–747.CrossRefGoogle ScholarPubMed
Forbes, J. M. 1977a. Models of the control of food intake and energy balance in ruminants. In Hunger Models: Quantitative Theory of Feeding Control (ed. Booth, D. A.). Academic Press, London. In press.Google Scholar
Forbes, J. M. 1977b. Development of a model of voluntary food intake and energy balance in lactating dairy cows. Anim. Prod. In press.Google Scholar
Forbes, J. M. and Boaz, T. G. 1965. Studies in the roughage and water intake of ewes. Anim. Prod. 7: 289 (Abstr.).Google Scholar
Graham, N. McC. 1969. The influence of body weight (fatness) on the energetic efficiency of adult sheep. Aust. J. agric. Res. 20: 375–385.Google Scholar
Hadjipieris, G. and Holmes, W. 1966. Studies on feed intake and feed utilisation by sheep. I. The voluntary feed intake of dry, pregnant and lactating ewes. J. agric. Sci., Camb. 66: 217–223.CrossRefGoogle Scholar
Holmes, E. G. and Fraser, F. J. 1965. An attempt to produce hyperphagia in sheep by electrical damage to the hypothalamus. Aust. J. biol. Sci. 18: 345–352.CrossRefGoogle ScholarPubMed
Joubert, D. M. and Ueckermann, L. 1971. A note on the effect of docking on fat deposition in fat-tailed sheep. Anim. Prod. 13: 191–192.Google Scholar
Liebelt, R. A., Ichinoe, S. and Nicholson, N. 1965. Regulatory influences of adipose tissue on food intake and body weight. Ann. N. Y. Acad. Sci. 131: 559–582.CrossRefGoogle ScholarPubMed
Monteiro, L. S. 1972. The control of appetite in lactating cows. Anim. Prod. 14: 263–281.Google Scholar
Muir, L. A., Hibbs, J. W., Conrad, H. R. and Smith, K. L. 1972. Effects of estrogen and progesterone on feed intake and hydroxyproline excretion following induced hypocalcemia in dairy cows. J. Dairy Sci. 55: 1613–1620.CrossRefGoogle ScholarPubMed
Pollock, A. M. 1975. Seasonal changes in appetite and sexual condition in red deer stags maintained on a six-month photoperiod. J. Physiol., Lond. 244: 95P–96P.Google Scholar
Reid, R. L. and Hinks, N. T. 1962. Studies on the carbohydrate metabolism of sheep. XVII. Feed requirements and voluntary feed intake in late pregnancy, with particular reference to prevention of hypoglycaemia and hyperketonaemia. Aust. J. agric. Res. 13: 1092–1111.CrossRefGoogle Scholar
Rice, R. W., Morris, J. G., Maeda, B. T. and Baldwin, R. L. 1974. Simulation of animal functions in models of production systems: ruminants on the range. Fedn Proc. Fedn Am. Socs exp. Biol. 33: 188–195.Google ScholarPubMed
Russel, A. J. F., Gunn, R. G. and Doney, J. M. 1968. Components of weight loss in pregnant hill ewes during winter. Anim. Prod. 10: 43–51.CrossRefGoogle Scholar
Schinckel, P. G. 1960. Variations in feed intake as a cause of variation in wool production of grazing sheep. Aust. J. agric. Res. 11: 585–594.CrossRefGoogle Scholar
Smith, R. C. G. and Williams, W. A. 1973. Model development for a deferred-grazing system. J. Range Mgmt 26: 454–460.CrossRefGoogle Scholar
Smith, R. C. G. and Williams, W. A. 1976. Deferred grazing of Mediterranean annual pasture for increased winter sheep production. Agric. Systems 1: 37–45.CrossRefGoogle Scholar
Tarttelin, M. F. 1969. The physiology of the ventromedial hypothalamus of the sheep with special reference to food and water intake. Ph.D. Thesis, Univ. London.Google Scholar
Treacher, T. T. 1970. Effects of nutrition in late pregnancy on subsequent milk production in ewes. Anim. Prod. 12: 23–36.Google Scholar